Search found 104 matches
- Thu Jan 12, 2012 10:12 am
- Forum: Technical Discussion
- Topic: Washers for Panel Switches
- Replies: 14
- Views: 3205
Re: Washers for Panel Switches
On a related note, who knows where I could get some isolating sleaves and or washers for a Switchcraft input jack? I'm going to try a multi star ground system. That means making the hole in the chassis and front panel bigger (approx 11.4mm, I think) to tet the shoulder washer seated. For less hassl...
- Mon Aug 03, 2009 10:31 am
- Forum: Technical Discussion
- Topic: Vox Night Train Schematic
- Replies: 31
- Views: 29089
Re: Vox Night Train Schematic
Only Mastervolume tandem pot schould be between the caps. That's only required for a fixed bias amp. The NT is cathode biased and should be able to work with a simpler arrangement (simpler even than the one drawn out in the OP's schematic). I have a Vox NT here and I will get around to opening it u...
- Mon Jun 15, 2009 9:44 am
- Forum: Technical Discussion
- Topic: Fender modded to true "vibrato"?Can make channels
- Replies: 7
- Views: 2049
Re: Fender modded to true "vibrato"?Can make channels
Yes, from memory, it uses 2.5 valves and has a LOT of circuit to go with them. Not at all easy to retrofit.
But it does sound lovely - I have a '62 brown Vibrasonic with it and it's really sweet.
But it does sound lovely - I have a '62 brown Vibrasonic with it and it's really sweet.
- Thu Nov 16, 2006 11:00 am
- Forum: Trainwreck Discussion
- Topic: Express Whistling
- Replies: 15
- Views: 5837
Re: Express Whistling
Reversed plate leads from the OT to the valve sockets? (you'd have positive feedback instead of negative feedback) Just temporarily disconnect the NFB lead to check.populartsl wrote:It gets even worse when i adjust the presence knob.
Any ideas of the problem chaps
Ben
- Tue Jul 18, 2006 7:42 pm
- Forum: Technical Discussion
- Topic: Power Scaling Schems?
- Replies: 29
- Views: 15358
Re: Power Scaling Schems?
Drive Comp is just a voltage dividing volume control. You put it between section of the amp that *isn't* PSed (usually the preamp) and the bit that is PSed. So it can reduce the drive to the PSed section when you dial down the B+ in the section that is. So it's almost always a PrePIMV or PostPIMV (d...
- Wed Jul 05, 2006 9:18 am
- Forum: Trainwreck Discussion
- Topic: Express and Liverpool Kits
- Replies: 36
- Views: 8751
Re: Express and Liverpool Kits
I don't know what milspec soldering is, but would genuinely like to find out, to see examples, and to try to understand what the technique might bring to the amp-making party. I am an old dog, but I'm always looking to learn new tricks :) FWIW, my guide (so far) in soldering has simply been what I'v...
- Tue Jul 04, 2006 5:07 pm
- Forum: Technical Discussion
- Topic: Schematic drawing program
- Replies: 29
- Views: 13069
Re: Schematic drawing program
Well, you can use any paint or photo editing program, and just cut and paste it together from basic building blocks (resistor symbols, caps, etc). That's how I do mine (e.g. http://www.ampmaker.com/pp18guide/pp18sc2.jpg) These low tech programs demand a bit more fiddling than a dedicated schematics ...
- Tue Jul 04, 2006 5:01 pm
- Forum: Technical Discussion
- Topic: Planning my first amp build
- Replies: 3
- Views: 2402
Re: Planning my first amp build
Welcome Mr Dog :) 1) A valve (what's a tube?) rectifier can make a tonal difference on some amps. Not on a single-ended amp (like the AX84 P1), though. The valve rectifier drops a little voltage when the amp's at idle and a bit more if it's a Class AB amp, cranked and you suddenly demand more curren...
- Tue Jun 27, 2006 12:50 pm
- Forum: Trainwreck Discussion
- Topic: constellation?
- Replies: 14
- Views: 5483
Re: constellation?
I thought that was one that's un-Trainwrecky?
- Sat Jun 24, 2006 2:21 pm
- Forum: Technical Discussion
- Topic: Can I mount preamp tubes horizontally?
- Replies: 4
- Views: 3174
Re: Can I mount preamp tubes horizontally?
Yup - you'll be fine. Most 1u and 2u rackmount pre and powr amps have horizontal valves without trouble.
Thanks for the link - I hadn't seen that one before, and I've been rounding up bits for a Firefly amp, so this is something else to think about.
Thanks for the link - I hadn't seen that one before, and I've been rounding up bits for a Firefly amp, so this is something else to think about.
- Thu Jun 22, 2006 9:44 am
- Forum: Technical Discussion
- Topic: 1" centers for 24mm pots?
- Replies: 11
- Views: 3207
Re: 1" centers for 24mm pots?
Maybe try it on a bit of scrap aluminium or thick cardboard first? Might have to be very precise on starting the hole.
The other complication is knobs, and ease of twiddling 'em.
The other complication is knobs, and ease of twiddling 'em.
- Sat Jun 17, 2006 12:13 pm
- Forum: Technical Discussion
- Topic: Pre/Post PI master?
- Replies: 13
- Views: 5595
Re: Pre/Post PI master?
I haven't really experienced a lot of amps that had great tone with the MV turned down. Find a Guytron; that's one approach that definitely works (not cheap!). B+ control (Power Scaling by London Power and Maven Peal's thingy) is another. Most people who put PPIMVs on their non-MV 50/100W Marshalls...
- Wed Jun 07, 2006 5:29 pm
- Forum: Trainwreck Discussion
- Topic: Am I about to blow up my cab?
- Replies: 6
- Views: 1734
Re: Am I about to blow up my cab?
No, your cab is limited to 60W maximum. Because the moment you try 61W, you're putting 30.5W through the 30W speaker. With dissimilar speakers, there's even more of a grey area due to the probability of different impedance curves - meaning that at some freqs, one speaker may have a lower impedance t...
- Tue Jun 06, 2006 9:52 pm
- Forum: Technical Discussion
- Topic: Headphone amp
- Replies: 11
- Views: 6328
Re: Headphone amp
My favourite is the Palmer PDI-03 (which can be a dummy load, too). I run that into my PC's cheapo sound card for direct recording*, with another output to a Behringer mixer into home monitors. The Behringer has the headphone output for when the PC's switched off. The PDI-03 is a studio staple and h...
- Tue Jun 06, 2006 11:57 am
- Forum: Trainwreck Discussion
- Topic: There's one up for sale....
- Replies: 6
- Views: 2731
Re: There's one up for sale....
I think Anyone who would pay that much for an amp is an idiot. Here we go! :) Wherever idiocy starts, it's waaayyy before we get to ultra-rare amps: * idiots who bought their Mrs a diamond ring? * idiots who spend more than $20 on a bottle of wine * idiots who buy cars new instead of nearly-new * i...